A Steam‐augmented Gas Turbine With Reheat Combustor for Surface Ships

Abstract

He earned a BA degree in chemistry from Indiana University, an MA degree in physical chemistry from Columbia University, a Ph.D in physical chemistry from Case Western Reserve University, an MS in mechanical engineering from George Washington University, and an MS in aerospace engineering from the University of Maryland. His professional experience includes research on rocket fuels, atomic oxygen, and ozone with Olin Corp. and research on fuel cells at the United Technology Research Laboratory. At CDNSWC, he worked on Navy fuel cells, super flywheels, MHD propulsion, closed-cycle Brayton engines, biphase turbines, and the steamaugmented gas turbines. During this time, he was briefly borrowed by the Naval Academy where he taught thermodynamics as an adjunct professor of mechanical engineering. He has published over thirty refereed papers (including one chapter of a book) in grey journals, and nine patents. ABSTRACTThe steam-augmented gas turbine (SAGT) concept has attracted attention because of its benign level of NO, emission, its increased fuel efficiency, and signiflcant, cost-effective increments of output power, particularly when moisture injection is increased to levels approaching 50% of air flow. Such high levels of moisture consumption distinguish the SAGT engine from commercial steam-injected gas turbines where steam flow may be less than 15% of air flow. At the high 50% levels, the SAGT burner would operate near stoichiometric combustion ratios with specific powers exceeding 570 hp-sedb.In a previous study, an intercooled, steam-augmented, gasturbine concept was examined for its applicability in the Navy's DDG-51 class ship environments, which achieves emciencies approaching the Navy's intercooled regenerative (ICR) engine, and an impressive compactness that arises from the high specific power of steam and low air consumption.A newer SAGT engine concept, described herein, dispenses with the intercooler, but adds a low-pressure reheat combustor. At the most efficient operating points, the efflciency of this new reheat SAGT engine at 43% exceeds the efficiency of the ICR engine, while exhibiting the compactness of the previous SAGT concept. Tabular and graphical simulation data comparing the baseline engine, with the ICR and other engine simulations, show that the maximum efficiency of the new SAGT engine occurs at powers required for cruising speeds. Since a DDG operates near cruise conditions for the majority of its mission time, a SAGT plant uses less fuel than the ICR plant. Moreover, since it eliminates the intercooler, developmental work on member elements, largely derivable from off-the-shelf components, is reduced. Even with conservative cost estimates, the SAGT plant is quite competitive on a first-acquisition cost basis with the current gas turbine in the fleet.